Starter mechanism for internal combustion engines



A. DOW 1,814,178

STARTER, MECHANISM FOR INTERNAL COMBUSTION ENGINES Aug. 4, 1931.

Filed May 14, 1930 2 Sheets-Sheet l n m H. W: a. p mm 3 mi N u r 0/ Ii a TA K mm? "3 4 VI B m T 2: i m T f u .m 7

A. DOW

Aug. 4, 1931.

STARTER MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed May 14,; 1930 2 Sheets-Sheet 2 4 exa/7oer 00w B 31% A TTORNE Y.

Patented Aug. 4, 1931 UNITED STATES PATENT OFFICE ALEXANDER DOW, OF NEW YORK, N. Y., ASSIGNOR TO DOW PATENTS HOLDING COR- PORATION, 1i. CGIRPORATION OF DELAWARE STARTER MECHANISM FOR- INTERNAL COMBUSTION ENGINES Application filed May 14-, 1930. Serial No. 452,502.

This invention is a starter mechanism for internal combustion engines and is of that general type wherein a pair of cooperating gripping members are adapted to friction ally grip and drive an interposed driven member, usually in the form of a ring carried by the crank shaft or fly wheel of an engine.

The primary object of the invention is to '10 provide a starting mechanism of the character described wherein the parts entering into the construction may be more economically manufactured and assembled than heretofore. This is accomplished by mounting 15 all of said parts directly upon the driving shaft of the starting mechanism in such sequence that they will cooperate to cause the gripping members to engage with and drive the driven member during starting operations and to free the grippingmembers from first, a fixed collar rigidly secured by a pin,

or otherwise, to the shaft to rotate therewith; neXt, a loose sleeve free for rotation and longitudinal sliding movement on the shaft, the adjacent ends of the collar and sleeve having gripping faces to engage an interposed driven member, and the loose sleeve having at its opposite end a cam face; next, a cam follower, keyed to slide longitudinally on the shaft and rotate therewith; and, lastadjusting element which may conveniently be a nut threaded on to the shaft. All of these elements are directly mounted on the shaft and individually depend upon the shaft for support.

Another object of the invention is to provide, in a starting mechanism of the character described means which will, under normal conditions, function as a substantially rigid strut to hold the gripping members in driving engagement with the driven member during starting operations but which means, nevertheless, has the characteristic that, under abnormal conditions, said means will resiliently yield while maintaining the desired driving engagement between the parts. The said means is preferably in the form of a spring normally held by an appropriate retainer under a predetermined minimum compression sufficiently high to cause said spring to be substantially neutral under. ordinary operating conditions, but sufliciently low to permit the spring to resiliently yield under abnormal conditions. This spring may be conveniently introduced into the assembly hereinbefore described, by interposing it somewhere between the adj acent element and the gripping face of the loose sleeve. In practice, it is, by preference, positioned between said adjusting element and the follower.

A further feature resides in the means whereby the gripping members are bot-h normally maintained free from contact with the ring, except when the gripping members are actually driving said ring.

Features of the invention, other than those specified, will be apparent from the hereinafter detailed description and claims, when read in conjunction with the accompanying drawings.

The accompanying drawings illustrate different practical embodiments of the invention, but the constructions therein shown are to be understood as illustrative, only, and not as defining the limits of the invention.

Figure 1 is a plan view of engine starter mechanism embodying the present invention. In this view a portion of the fly wheel and associated ring are shown in section.

Figure 2 shows the same construction as illustrated in Figure 1, but with the shaft rotated. through 90 degrees and the gripping members in engagement with the driven member. In this view, certain of said parts are shown in central section in the interest of clearness.

Figure 3 is a diagrammatic view showing the. development of the loose sleeve and he cam surfaces thereon.

"shaft -2 by mean armature shafts of conventional Figure 4 is a view corresponding to Figure 1, but showing, as an added element, resilient means interposed between the yoke and the adjusting nut to provide for the elastic engagement of the gripping members with the ring of the flywheel.

Figure 5 shows the same construction as illustrated in'Figure 4, but with the shaft turned through 90 degrees and with the grippi aane hhers in engag m n wi h. th driven member. In this view, certain of the parts are shown in central section in the interest of clearness. a

Figure 6 shows an entire starter motor assembly embodying the present invention in elev tio V Figure 7 shows a modified form starter a s m ly als mhed iha th ven n a with certain parts illustrated in central section- Y R f r ng t i he .wchaw s ticular-ly ,tp Figures 1 and 1 indicates ,a hea in h hln ay h mef th n h a h g off-th asi g et st hs m T i ,l g btor be of any conventional form and is provided with an armature shaft 2 extendbeyond the casing a sufiicient distance to accommodate the parts which, according to the present inyention, are associated therewith. Directly secured to the armature shaft adjacent the housing lis one friction member 3 of theassembly, This friction member is inthe formof a'collar firmly secured to the s of a ,pin lor in any other suitable manner.

,hrranged further along the shaft and havping member. The contiguous faces of the gripping members 3 and 5carrythe gripping ,6 and (and these faces are preferably of conical-form, whereby they areaclapted to cooperate with and grip the interposed ring 80f an engine fly wheel 9. A spring 10 is preferably interposed between the members 3 and 5-;and serves to force these members The slight lost motion commonly motors will permit freeing of the face 6 rom-enc s ment wi h i e 8 of th y wheel, as hereinafter more fully explained.

The end of the element 5 opposite .to' that A which carries the gripping face is formed wi h cam surfaces designated generally by the reference character 11 and hereinafter more fullydescribed and with these cam faces sadapted-tocooperate acam follower. The

,tQJlQue ish f m f a y l havin$a sleeye12 which has closesliding fitiwithrthe shaf file -keyed gain t ro a there n thy hesansh a k y 13. h s e re ar at its inner end two arms 14, and these two e shrca sv a h ler l whi me l'l '$9flysW l ,h alcain'srrhh llh ro er each have a trunnion farm and more par-- perforated to form a bearing for the trunnion of the associated roller.

The outer end of the shaft 2 is threaded as shown at 17 and on to this threaded portion of the shaft beyond the follower is screwed a castellated or slotted nut 18. The shaft is perforated or slotted'and a cotter pin 19 is adapted to be passed through the castellations of the nut 18 and through the perforationor slot of the shaft to lock the nut 18 in adjustment.

Inpractice, the starter is mounted in proximity with the engine which it is adapted to crank and is so positioned that the ring 8 of the flywheel will project between the gripping faces6 and 7 Thenut 18 is thereupon regulated to adjust the relative position between the partsof the starter with reference to said-ring which serves as a gauge for such ,adjustmen While the cam faces 11 to which I have" surface rises gradually vas indicated at 21,

and this gradual rise terminates in an abrupt ascent indicated at 22, which ispreferably in the form of an arc, the radius of whlch s substantially the radius of the roller zcooperatingtherewith. As a resultofzthis construction the rollers will normall .occu

v 7 r r I v the depressed seats 20 and when in this position thevspring 10 will .be free to force the gripping vmembers apart.

the shaft 2 rotated with rapid acceleration, the followers adyance out of thedepressions or seats 20' on ,to the gradual rising portion 21 of the cam faces and continue 'to so rise;

for the purposeof forcing the gripping memher 5 intoengage nent with the fly wheel ring and simultaneously reacting to vdraw the gripping memberfi into engagement with the oppositeside of said-ri-ng 8. Thisoperatien will proceed until the rollers engage the rapid ascents22 of thecamr faces which ascents will constitute in effect, stops to the further travel of the rollers over the cam faces, but the nut 18 is soadjusted that the engagement of the rolle W -h th stqp 9 h cam fa W occur simultaneously with the establishment of frict onal driying engagement between the gripping members and the fly wheel ring ,8.

tarts and gathers sufii When the engine s cient speed .to impart to the ring 8 a speed greater than the normal driving speed of the starting motor, the ring 8 thereupon rotate the gripping member Sataspeed greater than the speed of the armature shaft and causethe cam faces 11 to advance away from he a fol wy thi p ra i n, ecam Q lowe w ll b mu d 0 roll d wn t a faces to bring the rollers into the depressions .erseats to thereby releasethe fly wheel When the startin motor is ener iz d lld v a g ring from the gripping action of the members 8 and 5.

The structure shown'in Figures 4 and 5 is, in the main, substantially the same as that illustrated in Figures 1 and 2 with the addition of certain parts. Thus, it will be noted that the structure of Figures 4 and 5 embodies a bearing 1 for the shaft 2. The fixed gripping member 3 is secured to the shaft by the pin 4, while the gripping element 5 is loose on the shaft and cooperates with the member 3 to grip and drive the ring 8. The outboard end of the gripping member 5 has cam faces engaged by the rollers 15 carried by the arms 14: of the yoke and the yoke is provided with a sleeve 12 having a keyed connection 13 with the shaft 2. A nut 18 of castellated or slotted character is screwed on to the end of the shaft 2 and serves to adjust the yoke longitudinally of the shaft.

It will be noted, however, that the nut 18 instead of acting directly against the sleeve of the yoke coacts with said sleeve through an intermediate spring 28 which is interposed between the nut and the yoke, so that as the cam follower reacts against the nut 18, it does so through the interposed spring 23.

In practice, this spring may be of any suitable character and may coact with the parts in various ways for the carrying out of the purposes stated. Neverthless, the form of construction shown in'the drawings has been found to give highly satisfactory results and is preferred. Here the spring is shown of the helical type enclosed within an annular band or sleeve 24 of tubular section. In the opposite ends of the tubular section are washers 25 and 26 and the opposite ends of said section are spun over the outer faces of the washers to form a substantially closed cage in which the spring is housed. I may make the cage in other ways than as described, but the form shown is efficient and economical.

I have also found it highly desirable to house the spring within the cage with the spring under a predetermined minimum compression. which is appreciable. While this is not absolutely essential, it is highly desirable. Suppose. for example, that under ordinary driving conditions, a pressure of say 05 pounds is required to be exerted by the gripping members upon the ring, then I prefer that the normal compression of the spring within the cage be somewhat in excess of x pounds, so that under normal conditions of driving where the thickness of the ring is uniform throughout, the spring will be to all intents and purposes netural and the pres sure of the grippng members upon the ring will be positive. If, however, the ring 8 varies appreciably in thickness at different parts of its circumference or for other reasons a yielding of the gripping members in an axial direction is required, then, and in that event, the spring will yield when subjected to the increased reaction of the cam follower or to the action of the nut trans mitted to said nut through the shaft from the member 3, and the gripping members will continue to drive the ring in an efficient manner.

Another advantage of having the spring within the cage and which renders this construction the preferred construction is that the spring while under a predetermined minimum compression is adjustable longitudinally of the shaft to effect desired adjustment of the cam follower through rotation of the nut 18 without varying the normal tension of the spring.

It will of course be understood that the washers 25 and 26 are movable toward one another within the cage, so as to permit compression of the spring as stated. As shown in Figures at and 5, the sleeve 12 of the yoke is of reduced cross section for a portion of its length, so as to permit it to extend into the interior of the spring. The purpose of this arrangement is to minimize the length of the device, although so far as the operation is concerned the spring and cage unit might be interposed directly between the sleeve 12 and the nut 18 of Figure 1 if the shaft were made somewhat longer.

It is to be noted that while the structure of Figures 4 and 5 contemplates the employment of the spring as stated, the spring with its associated cage and washers may be entirely removed and the nut- 18 screwed, so as to cooperate directly with the end of the sleeve 12.

The springs 10 of Figures 1, 2, 4 and 5 serve to normally maintain the gripping members in separated relation with the cam "1 rollers 15 in the depressions 20. This is the normal condition of the parts and they re main so until it is desired to employ the starting mechanism to crank the engine with which the ring 8 is associated. When the LL starting motor is energized, the shaft 2 together with the gripping member 3 an d cam follower are separated and speeded up with rapid acceleration, while the inherent inertia of the gripping member 5 causes it to lag. There results a relative rotation between the cam follower and the member 5 which causes the rollers 15 to ride upon the cam surfaces of the member 5 and thereby force said member 5 into engagement with one face of the ring 8. A reactionary force acts through the cam follower to the shaft 2 and serves to draw said shaft in a direction to move the gripping element 3 into engagement with the other face of the ring 8 and thus these two forces cooperate to cause the ring. 8 to be tightly gripped between the gripping members 3 and 5, so that upon continued rotation of the parts which are carried by said shaft, the gripping member 5 the cam rollers and they will. rotate therewith, while the members 3 and 5 will drive the ring 8 for the purpose of cranking the engine. This operation will continue until the engine has been start-ed and commences to operate under its own power whereupon the ring 8 will be driven from the engine at a greater speed than the speed of the gripping members 3 and 5.

The drag of the armature upon the shaft 2 and member .3 will thereupon tend to slow down the operation of the gripping member 3, while the gripping member 5' will tend to travel at the speed of the ring 8 and consequently the member 5 will travel faster than will be caused to partake of retrograde movement down the cam surfaces and be returned into the depressions for the purpose of separating the gripping members from driving relation with the ring 8.

The spring 10 will separate these members i 3 and 5 during its operation, but it is of considerable importance that the members be also separated from contact with the ring 8, because if one of them continues to contact with this ring, undesirable wear and abrasion will result. Various means may be employed for insuring this latter separation. In Figure 6, a very satisfactory and practical arrangement is illustrated. Here the hearing 1 is shown as one of the end bearings of the armature shaft of a starting motor 27, the opposite end bearing of which is designated 28. The shaft 2 is extended beyond the bearing 28 and carries a A spring is interposed between the collar 29 and the bearing 28 and serves to'normally move the armature shaft2 to the left. This movement is limited by engagement of the gripping member 3 with the adjacent end of the bearing 1. Thus, when the motor is de-energized, the gripping member 3 is dis engaged from the ring 8 by the power of the spring 30, while the spring 10 will force the member 5 in the opposite direction to free it from contact with said ring. In this way both elements are normally maintained free from contact with the ring 8 in a simple and eflicient manner. It will be understood, however, that when the starting motor is energized to carry out an engine starting operation, the action between the cam follower and the cam face of the member 5 will become a predominating force well able to overcome the power of the spring 30 and entirely effectual to force the members 3 and 5 into driving engagement with the ring 8.

The arrangement shown in Figure 6 is particularly adapted for use with electric starting motors, but the invention of course is not limited to use with such motors, for any suitable source of power may be utilized for cranking purposes. Thus, as shown in Figure 7, the shaft 2 is mounted in an appropriate bearing 1, back of which a collar fixed collar 29.

31 is fixed to the shaft and between the collar 31 and the bearing 1 is interposed a spring 32 which functions inthe same mannor as the spring '30 of F igureG. The end of the shaft 2 is square as indicated at 33 and extends into a square socket 34 associated with the main power shaft 35 driven from any suitable prime mover. The squared conne'ctions 33 and 3& permits of longitudinal movement of the shaft 2 to allow the member 3 to be engaged with or disengaged from the ring 8. As is well known, there is sufiicient end play in the armature shaft of an electric motor such as shown in Fig. 6 to permit of a like movement.

In practically carrying out this invention, the springs 30 and 32 of Figures 5 and 6 may be positioned as shown in these figures or may operate in the same direction upon the shaft by acting through a center pm at the outboard end of the shaft 2 in either case. These details of construction are optional and the present invention is not confined to the specific detailed construction shown.

The various forms of the invention which are hereinbefore described and shown in the accompanying drawings embody numerous novel features, all of which are directed to the production of a starter of marked simplicity and efliciency and one susceptible of satisfactory quantity production with expeditious assemblyand a minimum of subsequent surfacing. As stated, the spring between the yoke and adjusting nut-is preferred though not essential. This preference rises out of the numerous advantages which its presence provides.

The drawings show the invention in its preferred practical forms, but the invention is to be understood as fully commensurate with the appended claims. 7

Having thus fully describedthe invention, what I claim as new and desire to secure by Letters Patent is:

1. A starting mechanism for internal combustion engines embodying a driving shaft suitably mounted for rotation, and means to rotate thesame, a plurality of elements arranged in sequence on said shaft ;the first element being a collar fixed on the shaft and having at one end a gripping facerthe next element being a sleeve free for rotation and longitudinal sliding movement on said shaft, one end of said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed collar to grip and drive an interposed driven member and the other end of the said sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said cam faces; and the last member being a member adjustable longitudinally on the shaft to adjust the relative position of the preceding elements;

and a driven member interposed between the gripping faces.

2. A starting mechanism for internal combustion engines embodying a driving shaft suitably mounted for rotation, and means to rotate the same, a plurality of elements arranged in sequence on said shaft ;the first element being a collar fixed on the shaft and having at one end a gripping face; the next element being a sleeve free for rotation and longitudinal sliding movement on said shaft,

one end of said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed collar to grip and drive an interposed driven member and the other end of the said sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said cam faces; and the last member being a member adjustable longitudinally on the shaft to adjust the relative position of the preceding elements; a driven member interposed between the gripping faces, and a resilient member interposed between the adjusting member and the gripping face of said sleeve. v

8. A starting mechanism for internal combustion engines embodying a driving shaft suitably mounted for rotation, and means to rotate the same, a plurality of elements arranged in sequence on said shaft ;the first element being a collar fixed on the shaft and having at one end a gripping face; the next element being-a sleeve free for rotation and longitudinal sliding movement on said shaft, one end of said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed collar to grip and drive an interposed driven member and the other end of the said sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said cam faces; and the-last member being a member adj ustable longitudinally on the shaft to adjust the relative position of the preceding elements; a driven member interposed between the gripping faces; a resilient member interposed between the adjusting member and the gripping face of said sleeve; and means to maintain said spring under a predetermined minimum compression.

4. A starting mechanism for internal combustion engines embodying a driving shaft suitably mounted for rotation, and means to rotate the same, a plurality of elements arranged in sequence on said shaft;the first element being a collar fixed on the shaft and having at one end a gripping face; the next element being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, one end of said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed collar to grip and drive an interposed driven member and the other end of the loose sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said cam faces; the next element being a spring; and the last member being a member adjust' able longitudinally on the shaft to adjust the relative position of the preceding elements; and a driven member interposed betweenthe gripping faces.

5. A starting mechanism for internal combustion engines embodying a driving shaft suitably mounted for rotation, and means to rotate the same, a plurality of elements arranged in sequence on said shaft ;the first element being a collar fixed on the shaft and having at one end a gripping face; the next element being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, one end of said sleeve having a gripping faoe adapted to cooperate with the gripping face of the fixed collar to grip and drive an interposed driven member and the other end of the loose sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said cam faces; the next element being a spring; and the last member being a member adjustable longitudinally on the shaft to adjust the relative position of the preceding elements; a driven member interposed between the gripping faces; and means to normally maintain said spring under a predetermined minimum compression.

6. A starting mechanism for internal combustion engines embodying a driving shaft suitably mounted for rotation and means to rotate the same, a plurality of elements arranged in sequence on said shaft ;the first element being a collar fixed on the shaft and having at one end a gripping face; the next element being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, one end of said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed collar to grip and drive an interposed driven member and the other end of said sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said cam faces; the next element being a spring maintained under sufficient compression to present a substantially rigid strut under normal operation, said spring being yieldable under abnormal reaction of the elements: and the last element being a member adjustable longitudinally on the shaft to adjust the relative position of the preceding elements; and a driven just the relative position of the faces of the collar and sleeve.

7. A starting mechanism for internal combustion engines embodying a driving shaft,

meansfor supporting and driving the shaft, said shaft projectingbeyond the supporting and driving means to form a support for a plurality of elements arranged in sequence on said shaft ;the first element being a collar fixed on the shaft adjacent said supporting and driving means and having at its outer end a gripping face; the next element being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, one end of said loose sleeve having a gripping face adapted to cooperate with the gripping face ofthe fixed collar to grip and drive aninten posed driven member and the other end of the sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on'the shaft; and the last element being a member adjustable longitudinally on the outboard end of the shaft to adpreceding elements; and a driven member interposed between the grippingfaces'o-f the collar and loose sleeve.

8. A starting mechanism for internal combustion engines embodying a driving shaft, means for supporting. and driving the shaft, said shaft projecting beyond the supporting and driving means to form a supportfor a plurality of elements arranged in sequence on said shaft ;--the first element being a collar fixed-on the shaft adjacent. said supporting-and driving means and having at its outer end a gripping face; the next element being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, the inner end of-said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed sleeve to grip and drive an interposed driven member and the other end-ofthe sleeve formed with suitable cam faces; the next element. being a-ca-mfollower mounted for rotation with and for longitudinal sliding-adjustment on the shaft;the last element being a member adjustable longitudinally on the out board end of the shaft. to adjust the relative position of the preceding elements, a driven member interposed between the gripping faces, and a resilient member interposed between the adjusting member and the gripping face of the loose sleeve. 7

9. A starting mechanism for internal comb-ustion engines embodying a driving shaft, means for supporting anddriving the shaft,

said shaft projecting beyond the supporting and driving means toform a support for a plurality of elements arranged in sequence onsaid shaft the first element being a col.- .lar fixed onthe shaft adjacent said supporting and driving means and havingat its outer end a gripping face; the next element being a loose sleeve free for rotation and longitudinal sliding movement on saidshaft, the inner end of said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed sleeve to grip and drive an interposed driven member and the other end of the sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft; the last element being a member adjust able longitudinally on the outboard end of the shaft to adjust the relative position of the preceding elements, a driven member interposed between the gripping faces, a resilient member interposed between the adjusting member and the gripping face of the loose sleeve; and means to maintain said spring under a predetermined minimum compression.

10. A starting mechanism for internal combustion engines embodying a driving shaft, means for supporting and driving the shaft, said shaft projecting beyond the supporting and drivlngmeans to form a support forv a plurality of elements arranged in sequence on said shaft ;the.first element being a collar fixed on the'shaft adjacent said sup porting and driving means andhaving at its outer end a gripping face ;.,the next element being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, the inner end-of said sleeve having a gripping face adapted to cooperate with the gripping face on the collar to grip and drive an i-nten posed driven member and the vother'end of the loose sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said camv faces; the next. element being aspring and the last elemenz. being a: member adjustable.longitudin ally on the outboard end of the shaft to adjust the relative position of the: preceding 7 elements, and a driven'member interposed beiween the gripping faces of the collar and sleeve.

11.. A starting mechanism for. internal combustion engines embodying a driving shaft, means for suppertingand driving the shaft, said shaft projecting beyond the sup porting and driving means toform support for a plurality of elements arranged in sequence on said shaft ;the first element being a collar fixed on the shaft adjacent said supporting and driving-means and having at its outer enda gripping face; the next ele ment being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, 2' he inner end of said; sleeve having; a gripping face adapted: to cooperate with the gripping face on the collar to grip-and drive aninterposed driven member andthe other end of the loose sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on ihe shaft and adapted to cooperate with said cam faces; the next element being a spring; and the last element being a member adjustable longitudinally on the outboard end of the shaft to adjust the relative position of the preceding elements; a driven member interposed between the gripping faces of the collar and sleeve, and means to normally maintain said spring under a predetermined minimum compression.

12. A starting mechanism for internal combustion engines embodying a driving shaft, means for supporting and driving the shaft, said shaft projecting beyond the supporting and driving means to form a support for a plurality of elements arranged in sequence on said shaft; the first element being a collar fixed on the shaft adjacent said supporting and driving means and having at its outer end a gripping face; the next element being a loose sleeve free for rotation and longitudinal sliding movement on said shaft, the inner end of said sleeve having a gripping face adapted to cooperate with the gripping face of the fixed collar to grip and drive an interposed driven member and the other end of the loose sleeve formed with suitable cam faces; the next element being a cam follower mounted for rotation with and for longitudinal sliding adjustment on the shaft and adapted to cooperate with said cam faces; the next element being a spring maintained un der sufficient compression to be substantially neutral under normal operation, said spring being yieldable under abnormal reaction of the elements; a member adjustable longitudinally on the outboard end of the shaft to adjust the relative position of the preceding elements; and a driven member interposed between the gripping faces of the collar and sleeve.

13. A starting mechanism for internal combustion engines embodying spaced apart gripping members adapted to grip and drive an interposed driven member, means for moving the gripping members into gripping relation with said driven member, and resilient means for taking up abnormal reaction between the elements, said means comprising a spring, and a retainer coacting with the spring to normally hold the spring under a predetermined minimum compression.

145. A starting mechanism for internal combustion engines embodying spaced apart gripping members adapted to grip and drive an interposed driven member, means for moving the gripping members into gripping relation with said driven member, resilient means for taking up abnormal reaction between the elements, said means comprising a spring, and a cage housing the spring and normally holding it under a predetermined, m nimum compression.

15. A starting mechanism for internal combustion engines embodying a pair of spaced apart gripping members adapted to engage with and drive an interposed driven member, one of said members havin a cam surface, and a. follower coacting wi h said cam surface and embodying a yoke provided with rollers engaging with the cam surface.

16. A starting mechanism for internal combustion engines embodying a driving shaft suitably mounted for rotation and means to rotate the same, two gripping members supported on adapted to grip and drive an interposed driven member, one of said members having a cam surface, and a follower coacting with said cam surface and supported on the shaft, said follower comprising a yoke having arms provided with bearings, and rollers having trunnions extending into said bearings, said rollers engagn with said cam face.

17. In an a mbly of the type described, the combination of an electric motor, an armature shaft therefor, said shaft being movable axially within said motor and having an extension, a member of an engine starting mechanism supported on and driven by said extension, said member being provided with a. conical surface, cross axial trunnions with rollers mounted on the shaft, a sleeve freely mounted. upon said shaft and having cam surfaces on one end thereof to coaet with said rollers, said sleeve having at the other end a conical surface adjacent and opposed to the conical surface on said member, adjust-able means to establish the position of said rollers with reference to said member, a. driven member interposed between said conical surfaces and adapted to be engaged and driven thereby, and springs coacting with the sleeve and with the armature said shaft in coaxial relation and shaft to normally impel the conical surfaces in directions away from the driven member.

18. In an engine starter, a shaft supported for rotary and axial movement, means to rotate said shaft, a. gripping member fixed on the shaft and having a gripping face, a sleeve loose with respect to the shaft for rotary and sliding movement axially of the of the shaft, said sleeve having at one end gripping faces adapted to cooperate with the gripping face of the fixed gripping member to grip and drive an interposed driven member, a driven member interposed between said gripping faces, said sleeve having at its other end a cam face, a follower secured to rotate with the shaft and adapted to cooperate with said cam face of the loose sleeve, to force said gripping faces into driving engagement with the driven member, and springs impelling the shaft and loose sleeve in opposite directions to normally hold said gripping faces free from contact With the driven member.

19. In an engine starter, a shaft supported for rotary and axial movement, means to rotate said shaft, a gripping member fixed on the shaft and having a gripping face, a sleeve loose With respect to the shaft for rotary and sliding movement axially of the shaft, said sleeve having at one end gripping faces adapted to cooperate with the gripping face of the. fixed gripping member to grip and drive an interposed driven member, a driven member interposed between said gripping faces, said sleeve having at its other end a cam face, a follower secured to rotate With the shaft and adapted to cooperate With said cam face of the loose sleeve, to force said gripping faces into driving engagement With the driven member, means normally impelling the shaft in a direction to disengage the fixed gripping member from contact With the driven member, and means normally impelling the-loose sleeve in the opposite direction to disengage it from said gripping member.

20. In a gas engine starter a shaft mounted for rotary and axial movement, gripping elements carried by said shaft, a driven element interposed between said gripping faces,-elastic means to normally separate said driven element and said gripping faces, and means to overpower said elastic means and to force said gripping faces into en 'agement with said driven element.

Signed by me at New York City this 10th day of May, 1930.

ALEXANDER DOWV. 

